Butler Creek Flip Open Scope ProtectorSimply the ultimate scope lens protection for hunters and shooters. Theyre custom fit to your scope, create a watertight, airtight seal and open with a touch of your thumb, so you can put your shot through the narrow window of opportunity in the most extreme conditions. Fast, flip open design keeps your eye on the target. Silent spring hinges wont spook game. Water tight, custom fit friction mounts anchor them to your scope. Air tight semi O ring